Download Subatomic Particles, Atomic Notation, Counting Atoms

SNC2D – Chemistry: Chemical Reactions
Subatomic Particles, Atomic Notation, Periodic Table
(p. 184-185)
Subatomic Particles:
Atoms are composed of 3 basic subatomic particles:
Particle Name and Symbol
Charge
Location in Atom
Protons (p+)
Positive
In the nucleus
Neutrons (n°)
Neutral
In the nucleus
Electrons (e-)
Negative
Moving around the nucleus
Atomic Notation:
Atomic notation is a concise, convenient way to give information about the atom
of an element.
General Format
A
Z
Example with Sodium
X – element symbol
X
A – atomic mass (#
protons + # neutrons)
23
11
Na
Z – atomic number (#
protons)
Na – symbol for
sodium
Atomic mass = 23 (#
protons + # neutrons
= 23)
Atomic number = 11
(# protons = 11)
To find the # of
neutrons = Mass # –
Atomic #
Examples and Practice:
35
17
Cl
# protons = 17
# electrons = 17
# neutrons = 35 – 17
= 18
56
26
# protons = 26
Fe
# electrons = 26
# neutrons = 56 – 26
= 30
SNC2D – Chemistry: Chemical Reactions
39
19
108
47
# protons = 19
K
19
9
# electrons = 1919
# protons = 99
F
# neutrons = 2039 –
19 = 20
Ag
# electrons = 9 9
# neutrons = 10
# protons = 47
# electrons = 47
# neutrons = 61
Practice Exercises:
a. Identify the elements which have the following numbers of protons in the
nuclei of their atoms:
8 _O-_oxygen_
30 _Zn-_zinc_
38 _Sr-strontium
82 _Pb-_lead_
b. Write the atomic notation for each of the following atoms:
a) An atom with 8 protons and 6 neutrons:
14
______ 8 O ________________
b) An atom with 6 protons and 6 neutrons:
______
12
6
C _______________
1
c) An atom with 1 proton and 0 neutrons: _______ 1 H ______________
80
d) An atom with 45 neutrons and 35 electrons: ___ 35 Br ____________
c. Name the element that:
a) has an atomic number of 7 and a mass number of 14:
__nitrogen___________
SNC2D – Chemistry: Chemical Reactions
b) has 10 protons and a mass number of 20: __neon_________________
c) has 17 electrons and 17 protons: __chlorine_______________
d) has 30 neutrons and a mass number of 56: ___iron________________
Teacher Demo
Reactivity of the Group 1 Alkali Metals (Demo)
Metal
Lithium
Observations (strength of the reaction, gas produced?
Etc.)
- heat, bubbles due to gas produced
Sodium
- Moved around dish, bubbles, more reactive than
lithium
Potassium
- Caught fire, heat, gas produced
The Elements Video
- tom Lehrer flash video
Alkali metals and myth busters – flash video
SNC2D – Chemistry: Chemical Reactions